WO2022141242A1

WO2022141242A1 - Control method and device

Info

Publication number: WO2022141242A1
Application number: PCT/CN2020/141597
Authority: WO
Inventors: 马文武; 曹毅; 任毛杰; 张劲松
Original assignee: 华为数字能源技术有限公司
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2022-07-07
Also published as: EP4253802A4; US12038082B1; CN115885119A8; CN115885119A; EP4253802A1

Abstract

A control method and device, which relate to the field of control, and can be applied to an electric drive system. The electric drive system comprises an oil pump (401), a motor (402), a speed reducer (403), and a housing (404). The motor (402) and the speed reducer (403) are disposed in the housing (404); lubricating oil is stored in the housing (404); the oil pump (401) is used for pumping the lubricating oil. The method comprises: acquiring a first rotation speed of the motor (402), a second rotation speed of the oil pump (401), and the temperature of the lubricating oil in the housing (404); and according to the first rotation speed, the second rotation speed, and the temperature, controlling the rotation speed of the oil pump (401) to be a third rotation speed. In this way, the height of the lubricating oil in the housing (404) and the power of the oil pump at different rotation speeds of the oil pump can be changed by adjusting the rotation speed of the oil pump (401), thereby effectively improving the efficiency of an assembly.

Description

A control method and device

technical field

The present application relates to the field of control, and in particular, to a control method and device.

Background technique

The electric drive assembly is the core component of new energy vehicles, and the pursuit of high efficiency of the electric drive assembly has become the mainstream development demand and trend. The improvement of the efficiency of the electric drive assembly system can improve the cruising range of the whole vehicle, and the cruising range is one of the most important performance indicators of new energy vehicles.

At present, an electronic oil pump is usually used to cool and actively lubricate the motor and the reducer. The function of the electronic oil pump is to send the lubricating oil to the friction parts of the motor, so that the lubricating oil circulates in the lubricating circuit to ensure that the motor is well cooled and lubricated. .

However, when the electronic oil pump is used to cool and lubricate the assembly motor and reducer, the assembly loss is relatively large, and the assembly efficiency is not effectively improved.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a control method and device, which can control the rotational speed of the oil pump to be a third rotational speed according to the first rotational speed of the motor, the second rotational speed of the oil pump, and the temperature of the lubricating oil. In this way, by adjusting the rotational speed of the oil pump, the height of the lubricating oil level in the casing can be actively controlled, and the fluid level of the lubricating oil inside the casing and the power of the oil pump can be changed under different oil pump rotational speeds, thereby effectively improving the efficiency of the assembly.

In the first aspect, an embodiment of the present application provides a control method, which is applied to an electric drive system. The electric drive system includes an oil pump, a motor, a reducer, and a casing. The motor and the reducer are arranged in the casing, and a lubricant is stored in the casing. Oil, the oil pump is used to pump the lubricating oil, and the method includes: obtaining the first rotational speed of the motor, the second rotational speed of the oil pump and the temperature of the lubricating oil in the casing; controlling the oil pump according to the first rotational speed, the second rotational speed and the temperature The rotational speed is the third rotational speed. In this way, the embodiments of the present application can adjust the rotational speed of the oil pump to change the level of lubricating oil inside the casing and the power of the oil pump under different rotational speeds of the oil pump, thereby effectively improving the assembly efficiency.

In a possible implementation manner, controlling the rotational speed of the oil pump to be the third rotational speed according to the first rotational speed, the second rotational speed and the temperature includes: determining a correlation relationship corresponding to the temperature according to the temperature, and the correlation relationship includes the rotational speed of the motor and the rotational speed of the oil pump. Correlation relationship with the loss; determine the first loss corresponding to the first rotational speed and the second rotational speed in the correlation relationship; control the rotational speed of the oil pump to be the third rotational speed according to the first loss and the correlation relationship. In this way, the embodiment of the present application can control the rotational speed of the oil pump through the correlation between the rotational speed of the motor, the rotational speed of the oil pump and the loss, so that the rotational speed of the oil pump can be controlled more accurately, thereby effectively improving the overall efficiency.

In a possible implementation manner, controlling the rotational speed of the oil pump to be the third rotational speed according to the first loss and the correlation relationship includes: determining a plurality of second losses corresponding to the first rotational speed in the correlation relationship; In the case of less than the first loss, the rotational speed of the oil pump is adjusted to be the third rotational speed, where the third rotational speed is the rotational speed of the oil pump corresponding to one of the second losses. In the embodiment of the present application, the rotational speed of the oil pump is adjusted to the rotational speed corresponding to the smaller loss, so that the assembly efficiency can be effectively improved.

In a possible implementation manner, when one of the second losses is smaller than the first loss, adjusting the rotational speed of the oil pump to the third rotational speed includes: adjusting the oil pump when the plurality of second losses are smaller than the first losses The rotational speed of is the third rotational speed, wherein the third rotational speed is the oil pump rotational speed corresponding to the lowest loss among the plurality of second losses. In this way, the speed of the oil pump can be adjusted to minimize the loss, thereby improving the overall efficiency more effectively.

In a possible implementation manner, the loss includes: oil churning loss and oil pump power consumption; wherein, the oil churning loss is the power loss caused by the liquid resistance caused by the rotation of the reducer gear in the lubricating oil in the casing.

In a possible implementation manner, in the correlation relationship, the motor speed, the oil pump speed and the loss are a continuous functional relationship. In this way, multiple second losses corresponding to the first rotational speed can be determined more accurately, so that the rotational speed of the oil pump can be adjusted to the rotational speed corresponding to the lowest loss, and the overall efficiency can be improved more effectively.

In the second aspect, an embodiment of the present application provides a control device, which is applied to an electric drive system. The electric drive system includes an oil pump, a motor, a reducer, and a casing. The motor and the reducer are arranged in the casing, and a lubricant is stored in the casing. Oil, oil pump is used to pump lubricating oil.

The control device may be a terminal device, or may be a chip or a chip system in the terminal device. The control device may comprise a processing unit. When the control device is a terminal device, the processing unit may be a processor. The control device may further include a storage unit, which may be a memory. The storage unit is used for storing instructions, and the processing unit executes the instructions stored in the storage unit, so that the terminal device implements a control method described in the first aspect or any possible implementation manner of the first aspect. When the control device is a chip or a chip system in the terminal device, the processing unit may be a processor. The processing unit executes the instructions stored in the storage unit, so that the terminal device implements a control method described in the first aspect or any possible implementation manner of the first aspect. The storage unit may be a storage unit in the chip (for example, a register, a cache, etc.), or a storage unit in the terminal device located outside the chip (for example, a read-only memory, a random access memory, etc.)

Exemplarily, the processing unit is used to obtain the first rotational speed of the motor, the second rotational speed of the oil pump and the temperature of the lubricating oil in the casing; the processing unit is also used to control the oil pump according to the first rotational speed, the second rotational speed and the temperature. The rotational speed is the third rotational speed.

In a possible implementation manner, the processing unit is further configured to determine the correlation relationship corresponding to the temperature according to the temperature, and the correlation relationship includes the correlation relationship between the motor speed, the oil pump speed and the loss; The first loss corresponding to the first rotation speed and the second rotation speed is determined in the relationship; the processing unit is further configured to control the rotation speed of the oil pump to be the third rotation speed according to the first loss and the correlation relationship.

In a possible implementation manner, the processing unit is further configured to determine a plurality of second losses corresponding to the first rotational speed in the correlation relationship; in the case where one of the second losses is smaller than the first loss, adjust the rotational speed of the oil pump is the third rotational speed, wherein the third rotational speed is the rotational speed of the oil pump corresponding to one of the second losses.

In a possible implementation manner, the processing unit is further configured to: in the case that the plurality of second losses are smaller than the first losses, adjust the rotational speed of the oil pump to be a third rotational speed, where the third rotational speed is a plurality of second losses The oil pump speed corresponding to the lowest loss among the losses.

In a possible implementation manner, in the correlation relationship, the motor speed, the oil pump speed and the loss are a continuous functional relationship.

In a third aspect, an embodiment of the present application provides a control apparatus, including: a processor configured to invoke a program in a memory to implement the first aspect or any control method in any possible implementation manner of the first aspect.

In a fourth aspect, the present application further provides a powertrain, comprising the second aspect or any control device in any possible implementation manner of the second aspect, the powertrain further comprising: an inverter, a motor, and a reducer . Among them, the inverter is used to convert the direct current into alternating current and then transmit it to the motor; the motor is used to convert the alternating current into mechanical energy to drive the vehicle; the reducer is used to convert the output speed of the motor shaft of the motor.

In a fifth aspect, the present application further provides a vehicle, including the powertrain of the fourth aspect and a power battery pack, where the power battery pack is used to provide DC power for an inverter.

In a sixth aspect, an embodiment of the present application provides a chip, including: a processor and an interface circuit, where the interface circuit is used to communicate with other devices, and the processor processor is used to run a computer program or instruction to perform any implementation of the first aspect The control method described in any of the above.

Wherein, the communication interface in the chip may be an input/output interface, a pin, a circuit, or the like.

In a possible implementation, the chip or chip system described above in this application further includes at least one memory, where instructions are stored in the at least one memory. The memory may be a storage unit inside the chip, such as a register, a cache, etc., or a storage unit of the chip (eg, a read-only memory, a random access memory, etc.).

In a seventh aspect, an embodiment of the present application provides a computer-readable storage medium, where a computer program or instruction is stored in the computer-readable storage medium, and when the computer program or instruction is run on a computer, the computer is made to execute any one of the first aspect. A control method described in Implementation.

It should be understood that the second to seventh aspects of the embodiments of the present application correspond to the technical solutions of the first aspect of the embodiments of the present application, and the beneficial effects obtained by each aspect and the corresponding feasible implementation manner are similar, and will not be repeated here. .

Description of drawings

1 is a schematic diagram of a water-cooled motor electric drive assembly provided by an embodiment of the present application;

2 is a schematic diagram of the oil churning situation of the reducer when a water cooling method is used to dissipate heat according to an embodiment of the present application;

3 is a schematic diagram of an oil-cooled motor electric drive assembly provided by an embodiment of the application;

4 is a schematic diagram of an electric drive assembly system provided by an embodiment of the present application;

5 is a schematic diagram of a basic structure inside a motor according to an embodiment of the present application;

6 is a schematic flowchart of a control method provided by an embodiment of the present application;

FIG. 7 is a schematic diagram of obtaining a first rotational speed of a motor according to an embodiment of the present application;

8 is a schematic flowchart of a control method provided by an embodiment of the present application;

9 is a schematic flowchart of a control method provided by an embodiment of the present application;

10 is a schematic structural diagram of a control device provided by an embodiment of the application;

11 is a schematic structural diagram of a powertrain provided by an embodiment of the application;

12 is a schematic structural diagram of a vehicle according to an embodiment of the application;

FIG. 13 is a schematic structural diagram of a chip provided by an embodiment of the present application.

Detailed ways

In order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish the same or similar items with basically the same function and effect. For example, the first rotational speed and the second rotational speed are only used to distinguish the rotational speeds of the oil pump and the motor, and do not limit their order. Those skilled in the art can understand that the words "first", "second" and the like do not limit the quantity and execution order, and the words "first", "second" and the like are not necessarily different.

It should be noted that, in this application, words such as "exemplary" or "for example" are used to represent examples, illustrations or illustrations. Any embodiment or design described in this application as "exemplary" or "such as" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present the related concepts in a specific manner.

In this application, "at least one" means one or more, and "plurality" means two or more. "And/or", which describes the association relationship of the associated objects, indicates that there can be three kinds of relationships, for example, A and/or B, which can indicate: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A, B can be singular or plural. The character "/" generally indicates that the associated objects are an "or" relationship. "At least one item(s) below" or similar expressions thereof refer to any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (a) of a, b, or c can represent: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, c may be single or multiple .

The electric drive assembly system may include: a motor controller, a motor and a reducer. Among them, the efficiency loss of each part will affect the efficiency of the electric drive assembly system, thereby affecting the cruising range of the vehicle. Among them, the oil churning loss of the reducer gear is an important part of the efficiency loss of the electric drive assembly system.

Usually, when the motor is running at high speed, the motor stator will generate a lot of heat. If the heat dissipation is not carried out in time, it will seriously affect the working reliability of the motor and the performance of the whole vehicle. Therefore, it is necessary to dissipate heat from the motor.

At present, the commonly used motor cooling methods can include water cooling and oil cooling.

Exemplarily, FIG. 1 is a schematic diagram of an electric drive assembly of a water-cooled motor. As shown in FIG. 1 , the stator of the motor uses cooling liquid (eg, antifreeze) for heat dissipation, and the reducer uses lubricating oil for lubrication. For example, heat is removed from the motor by using a water pump to drive the coolant to speed up the flow.

Among them, the lubricating oil is located in the casing, and the reducer uses the main reduction gear to churning oil to splash and lubricate the gears and bearings. For example, Figure 2 is a schematic diagram of the oil churning of the reducer when water cooling is used for heat dissipation. The reducer consists of several gears. , shaft and bearings and other parts, the gear part of the reducer is immersed in the oil pool, and the lubricating oil is brought to the meshing tooth surface through the rotation of the gear for lubrication. In order to prevent excessive power loss during oil churning, the depth of the gear immersion in the oil pool should not be too deep. For example, the depth of the gear immersion in the oil pool can be a quarter of the gear radius. The distance between the top of the main reduction gear and the bottom of the casing can be greater than 5mm, to avoid the sludge or debris at the bottom of the oil pool covering the gear meshing surface and aggravating friction.

However, in order to achieve good lubrication of gears and bearings when the motor is cooled by water cooling, the amount of lubricating oil is required to be large and the liquid level is high, resulting in high oil churning loss generated by the reducer gear, and the liquid level of the lubricating oil is high. The height cannot be adjusted with changes in assembly conditions. It can be understood that after the amount of lubricating oil is determined, the churning loss is also fixed, and the churning loss cannot be optimized.

Exemplarily, Figure 3 shows a schematic diagram of using oil cooling to dissipate heat from the motor. As shown in Figure 3, an electronic oil pump can be used to pump out the lubricating oil in the casing to achieve cooling and active lubrication of the motor and the reducer. .

When oil cooling is used to dissipate heat to the motor, since the lubricating oil circulation circuit has a certain oil storage function, the liquid level of the reducer can be reduced, thereby reducing the oil churning loss. However, when the oil pump is used for cooling and lubrication, only the heat dissipation and lubrication of the assembly are considered, and the liquid level of the lubricating oil in the cavity is not adjusted actively through the oil pump to optimize the oil churning loss. Therefore, under different assembly operating conditions The churning losses below are not optimal.

Based on the problems existing in the above two methods, the embodiment of the present application provides a control method, which can effectively improve the assembly efficiency by adjusting the rotational speed of the oil pump to change the lubricating oil level in the cavity and the power of the oil pump under different rotational speeds of the oil pump. .

The control methods provided in the embodiments of the present application can be applied to the powertrain system shown in FIG. 4 . The powertrain system 400 may include an oil pump 401 , a motor 402 , a speed reducer 403 and a casing 404 .

The motor 402 and the reducer 403 are arranged in the casing 404 , the casing stores lubricating oil, and the oil pump 401 is used to pump the lubricating oil to realize cooling and lubrication of the motor 402 and the reducer 403 .

The motor 402 is an electromagnetic device that realizes electric energy conversion or transmission according to the law of electromagnetic induction, and its main function is to generate driving torque to generate power for electrical appliances or various machines. Specifically, the motor 402 can be applied to electric vehicles, for example, pure electric vehicles, extended-range electric vehicles, hybrid electric vehicles, fuel cell vehicles, new energy vehicles, and the like.

FIG. 5 shows a schematic diagram of the internal structure of a motor. As shown in FIG. 5 , the motor 500 mainly includes: a stator 510 , a rotating shaft 540 , a rotor 550 , a housing 560 , a front end cover 570 , a rear end cover 580 and a motor bearing 590 . The stator 510 is wound with a stator winding, and when the stator winding is wound, its two ends will extend outward from both ends of the stator core to form ends 5301 and 5302 of the stator winding. The relationship between the various components of the motor is as follows: the inner walls of the casing 560, the front end cover 570 and the rear end cover 580 form a cavity, and the cavity is provided with a stator 510, a rotor 550 and a rotating shaft 540 in sequence from the outer ring to the inner ring. That is to say, the rotor 550 is placed outside the rotating shaft 540 , and the setter 510 is placed on the rotor 550 . In addition, the stator 510 is fixed in the casing 560 , and the rotor 550 drives the rotating shaft 540 to rotate. Both ends of the rotating shaft 540 are rotatably connected to the two opposite side end faces (the front end cover 570 and the rear end cover 580 ) of the housing 560 through the motor bearing 590 respectively, and one end of the shaft 540 can also be connected to the input shaft gear of the reducer from one side end face.

The reducer 403 includes a parallel shaft gear reduction mechanism and a planetary gear reduction mechanism, and the input gear of each parallel shaft gear reduction mechanism is connected with a motor 402, and the output gear is connected with a driving member of a planetary gear reduction mechanism, and each planetary gear is reduced in speed The follower of the mechanism is connected to a power take-off shaft. Since the gears in the parallel shaft gear reduction mechanism are less difficult to process at the same speed, the parallel shaft gear reduction mechanism is directly connected to the drive motor, and then the planetary gear reduction mechanism is connected to the parallel shaft gear reduction mechanism. The speed of the gear reduction mechanism, thereby reducing the requirements for the gear machining accuracy of the planetary gear reduction mechanism.

The technical solutions of the present application and how the technical solutions of the present application solve the above-mentioned technical problems will be described in detail below with specific examples. The following specific embodiments can be implemented independently or combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

FIG. 6 is a schematic flowchart of a control method provided by an embodiment of the present application, and the method is applicable to the powertrain system corresponding to FIG. 4 above. As shown in FIG. 6 , a control method provided by an embodiment of the present application may include the following steps:

S601: Obtain the first rotational speed of the motor, the second rotational speed of the oil pump, and the temperature of the lubricating oil in the casing.

In a possible way of understanding, the first rotational speed of the motor is the rotational speed of the rotor of the motor.

In a possible implementation manner, the first rotational speed of the motor may be acquired through a photoelectric sensor. Wherein, the photoelectric sensor may include a projection photoelectric sensor or a reflective photoelectric sensor. Exemplarily, a schematic diagram of using a projected photoelectric sensor to acquire the first rotational speed of the motor is shown in FIG. 7 . Install a test disk on the motor shaft of the electric vehicle under test, for example, a toothed disk or a hole disk, and the disk has Z uniform tooth slots or round holes. Wherein, Z can be 60 or an integer multiple of 60. When the light beam passes through the slot or the small hole, it is projected on the photodiode to generate an electrical signal. When the light beam is blocked by the non-hole part of the disc, the photodiode has no signal, so the frequency of the pulse signal generated by the photodiode is proportional to the motor speed. .

In a possible implementation manner, the temperature of the lubricating oil in the casing may be acquired by a temperature sensor.

It can be understood that the first rotational speed of the motor, the second rotational speed of the oil pump and the temperature of the lubricating oil in the casing can also be acquired in any possible form, and the specific manner of acquisition is not limited in the embodiments of the present application.

S602: Control the rotational speed of the oil pump to be a third rotational speed according to the first rotational speed, the second rotational speed and the temperature.

In a possible implementation manner, the first rotational speed, the second rotational speed and the temperature may be input into the pre-trained model, and the obtained output result is the third rotational speed of the oil pump.

In a possible implementation manner, the first rotational speed, the second rotational speed and the temperature may be input into a pre-obtained calculation formula, and the third rotational speed of the oil pump can be obtained through calculation.

In a possible implementation manner, different oil pump rotational speeds and motor rotational speeds are obtained through multiple tests, and a table corresponding to the relationship between oil temperature, oil pump rotational speed and motor rotational speed is established. By looking up the table, it is determined that the rotational speed of the oil pump is the third rotational speed.

In the embodiments of the present application, other possible methods may also be used in combination with actual application scenarios to control the rotational speed of the oil pump to be the third rotational speed according to the first rotational speed, the second rotational speed, and the temperature, which is not limited in the embodiments of the present application.

In the embodiment of the present application, the height of the lubricating oil level in the casing can be actively controlled by adjusting the rotational speed of the oil pump, and the fluid level of the lubricating oil inside the cavity and the power of the oil pump can be changed under different rotational speeds of the oil pump, thereby effectively improving the assembly efficiency .

On the basis of the embodiment corresponding to FIG. 1 , in a possible implementation manner, as shown in FIG. 8 , S602 includes:

S801: Determine a correlation relationship corresponding to the temperature according to the temperature, and the correlation relationship includes the correlation relationship between the motor speed, the oil pump speed and the loss.

In a possible implementation, the losses may be aggregate losses. Among them, the assembly loss can include: motor loss, bearing loss, oil churning loss and oil pump power consumption. The oil churning loss is related to the liquid level of the lubricating oil in the casing, and the power consumption of the oil pump is related to the speed of the oil pump.

In a possible implementation, the losses may include one or more of the total losses.

In a possible implementation manner, the association relationship may be prior knowledge. The prior knowledge may be a table established by testing the relationship between different oil pump speeds and motor speeds and corresponding losses under different oil temperatures. By querying the table, the correlation relationship corresponding to the obtained lubricating oil temperature is obtained.

It can be understood that the association relationship in the embodiment of the present application may also be a column graph or a broken line graph, or other forms of expression, which are not specifically limited in the embodiment of the present application.

S802: Determine the first loss corresponding to the first rotational speed and the second rotational speed in the association relationship.

In a possible way of understanding, the first loss may be an assembly loss corresponding to the first rotational speed and the second rotational speed, or the first loss may include one or more of assembly losses.

In a possible implementation manner, the first loss corresponding to the first rotational speed and the second rotational speed may be determined by querying a table.

Exemplarily, when the oil temperature is 30° C., 40° C., 50° C. and 60° C., respectively, the table established by the relationship between different oil pump rotational speeds and motor rotational speeds and corresponding losses can be tested. Understandably, four tables can be obtained. When the obtained oil temperature is 30°C, the first speed and the second speed corresponding to the first speed in the table can be determined by querying the relationship between different oil pump speeds and motor speeds and the corresponding losses when the oil temperature is 30°C. loss.

S803: Control the rotational speed of the oil pump to be the third rotational speed according to the first loss and the correlation.

In a possible implementation manner, according to the first loss corresponding to the first rotational speed and the second rotational speed, in the obtained correlation relationship corresponding to the temperature of the lubricating oil, a plurality of loss values corresponding to the first rotational speed are determined, and among the plurality of loss values Determine if there is a loss value smaller than the first loss. When there is a loss value smaller than the first loss, the third rotational speed is a rotational speed corresponding to one of the loss values smaller than the first loss. When there is no loss value smaller than the first loss, the rotational speed of the oil pump is controlled to remain unchanged, and it can be understood that the third rotational speed is the same as the second rotational speed.

In a possible implementation manner, according to the first loss corresponding to the first rotational speed and the second rotational speed, in the acquired correlation relationship corresponding to the temperature of the lubricating oil, a plurality of loss values corresponding to the first rotational speed are determined. Determine whether there is a loss value smaller than the first loss among the multiple loss values, and adjust the oil pump rotational speed to one of the multiple loss values smaller than the first loss when there are multiple loss values smaller than the first loss The speed corresponding to the lowest loss. When there is no loss value smaller than the first loss, the rotational speed of the oil pump is controlled to remain unchanged, and it can be understood that the third rotational speed is the same as the second rotational speed.

In the embodiment of the present application, the rotational speed of the oil pump can be controlled by the relationship between the rotational speed of the motor, the rotational speed of the oil pump and the loss, so that the rotational speed of the oil pump can be adjusted more accurately, thereby effectively improving the overall efficiency.

On the basis of the embodiment corresponding to FIG. 8 , in a possible implementation manner, the losses include: oil churning losses and oil pump power consumption.

Among them, the churning loss is the power loss caused by the liquid resistance caused by the rotation of the reducer gear in the lubricating oil of the casing. The power consumption of the oil pump is related to the speed of the oil pump. For example, the faster the speed of the oil pump, the greater the power consumption of the oil pump; the smaller the speed of the oil pump, the greater the power consumption of the oil pump.

In a possible way of understanding, the churning loss is related to the liquid level of the lubricating oil of the casing, and the liquid level of the lubricating oil of the casing is related to the rotational speed of the oil pump. For example, the faster the oil pump rotates, the more lubricating oil is pumped, the less oil in the lubricating oil of the casing, and the lower the liquid level, which causes the gear of the reducer to rotate in the lubricating oil of the casing and is caused by the liquid resistance. The smaller the power loss, the smaller the corresponding churning loss. On the contrary, the slower the speed of the oil pump is, the less lubricating oil is pumped, and the higher the liquid level of the lubricating oil in the casing, the greater the power loss caused by the liquid resistance caused by the rotation of the reducer gear in the lubricating oil of the casing. , so the corresponding churning loss is larger.

In the embodiment of the present application, the rotational speed of the oil pump is adjusted according to the first rotational speed of the motor and the oil temperature of the lubricating oil, the oil amount of the lubricating oil in the cavity of the motor reducer can be changed, and the height of the oil churning liquid level can be adjusted, thereby controlling the oil churning loss and the The sum of the power consumption of the oil pump is the smallest. In this way, the loss of the assembly can be reduced and the efficiency of the assembly can be improved.

On the basis of the embodiment corresponding to FIG. 8 , in a possible implementation manner, as shown in FIG. 9 , S803 includes:

S901: Determine a plurality of second losses corresponding to the first rotational speed in the association relationship.

In a possible implementation manner, the association relationship may be prior knowledge. The prior knowledge may be a table established by testing the relationship between different oil pump speeds and motor speeds and corresponding losses under different oil temperatures. By querying the table, a plurality of second losses corresponding to the first rotational speed are determined in the correlation relationship. Among them, losses include: churning losses and oil pump power consumption.

S902: In the case that one of the second losses is smaller than the first loss, adjust the rotational speed of the oil pump to be the third rotational speed.

Wherein, the third rotational speed is the rotational speed of the oil pump corresponding to the one of the second losses.

Exemplarily, Table 1 is a table based on the relationship between different oil pump rotational speeds and motor rotational speeds and corresponding losses when the oil temperature is 40°C.

Table 1

If the obtained lubricating oil temperature is 40°C, the first rotational speed is 300, and the second rotational speed is 500, it can be determined by looking up the table that the first loss corresponding to the first rotational speed and the second rotational speed is 134.9195812, and the corresponding first rotational speed is 134.9195812. The multiple second losses are 137.4877539, 136.7111623, 129.3901122, and 149.8224251. Wherein, one of the second losses 129.3901122 among the plurality of second losses is smaller than the first loss, and the third rotational speed is the oil pump rotational speed 1500 corresponding to the second loss 129.3901122.

If the obtained lubricating oil temperature is 40°C, the first rotational speed is 300, and the second rotational speed is 1000, it can be determined by looking up the table that the first loss corresponding to the first rotational speed and the second rotational speed is 136.7111623, and the corresponding first rotational speed is 136.7111623. The multiple second losses are 137.4877539, 134.9195812, 129.3901122, and 149.8224251, respectively. Among them, the second loss 129.3901122 and 134.9195812 are both smaller than the first loss, then the third speed is the oil pump speed 1500 corresponding to the second loss 129.3901122, or the third speed is the oil pump speed 500 corresponding to the second loss 134.9195812.

In a possible implementation manner, when one of the second losses is smaller than the first loss, and when the rotational speed of the oil pump corresponding to one of the second losses is not less than the second rotational speed, adjust the rotational speed of the oil pump to the oil pump corresponding to the second loss. Rotating speed. When the rotational speed of the oil pump corresponding to the second loss is smaller than the second rotational speed, the third rotational speed keeps the original second rotational speed unchanged.

In a possible way of understanding, under different working conditions, when the amount of lubricating oil reaches a certain value, the cooling and lubrication requirements of the assembly system can be guaranteed. When the rotational speed of the oil pump is adjusted to a rotational speed lower than the second rotational speed, the amount of oil pumped by the oil pump is reduced, which may cause a problem that the cooling and lubrication requirements cannot be met. Therefore, in order to ensure the cooling and lubrication requirements of the assembly system, the third rotational speed can be adjusted so that the rotational speed of the oil pump corresponding to the second loss is not less than the rotational speed of the oil pump corresponding to the second rotational speed. In this way, the assembly efficiency can be effectively improved on the premise of meeting the cooling and lubrication requirements of the assembly system.

Exemplarily, as shown in Table 1, if the obtained lubricating oil temperature is 40°C, the first rotation speed is 400, and the second rotation speed is 500, the first rotation speed corresponding to the first rotation speed and the second rotation speed can be determined by looking up the table. The loss is 242.16, and the multiple second losses corresponding to the first rotational speed are 254.7495079, 242.3020135, 213.3399312, and 262.8393466, respectively. Among them, the second loss 129.3901122 is less than the first loss, and the oil pump speed 1500 corresponding to the second loss 213.3399312 is not less than the second speed 500, then the third speed is the second loss 213.3399312 The corresponding oil pump speed 1500.

If the obtained lubricating oil temperature is 40°C, the first rotational speed is 100, and the second rotational speed is 500, it can be determined by looking up the table that the first loss corresponding to the first rotational speed and the second rotational speed is 19.10806283, and the corresponding first rotational speed is 19.10806283. The multiple second losses are 14.88473822, 19.75720568, 21.43655737, and 23.62649258. Among them, the second loss 14.88473822 is smaller than the first loss, but the oil pump speed 0 corresponding to the second loss 14.88473822 is less than the second speed 500, so the oil pump keeps the original second speed unchanged.

In the embodiment of the present application, a plurality of second losses corresponding to the first rotational speed are determined in the correlation relationship, and in the case that one of the second losses is smaller than the first loss, the rotational speed of the oil pump is adjusted to the rotational speed of the oil pump corresponding to one of the second losses, In this way, by adjusting the rotational speed of the oil pump, the liquid level of the lubricating oil in the cavity and the power of the oil pump can be changed under different rotational speeds of the oil pump, thereby effectively improving the efficiency of the assembly.

On the basis of the embodiment of FIG. 9 , in a possible implementation manner, S902 includes: in the case that the plurality of second losses are smaller than the first losses, adjusting the rotational speed of the oil pump to be corresponding to the lowest loss among the plurality of second losses Oil pump speed.

If the obtained lubricating oil temperature is 40°C, the first rotational speed is 300, and the second rotational speed is 1000, it can be determined by looking up the table that the first loss corresponding to the first rotational speed and the second rotational speed is 136.7111623, and the corresponding first rotational speed is 136.7111623. The multiple second losses are 137.4877539, 134.9195812, 129.3901122, and 149.8224251, respectively. Among them, the second losses 129.3901122 and 134.9195812 are both smaller than the first losses, and the third rotational speed is the oil pump rotational speed 1500 corresponding to the lowest loss 129.3901122 among the plurality of second losses.

In a possible implementation, when the multiple second losses are less than the first loss, and when the oil pump speed corresponding to the multiple second losses is not less than the second speed, the third speed is the lowest loss among the multiple second losses. Corresponding oil pump speed.

Exemplarily, as shown in Table 1, if the obtained lubricating oil temperature is 40°C, the first rotation speed is 200, and the second rotation speed is 1000, the first rotation speed corresponding to the first rotation speed and the second rotation speed can be determined by looking up the table. The loss is 100.1577143, and the multiple second losses corresponding to the first speed are 24.91105675, 117.8515183, 116.3571159, and 28.18579267, respectively. Among them, the second loss 24.91105675 and 28.18579267 is less than the first loss, but the oil pump speed 0 corresponding to the second loss 24.91105675 is less than the second speed, and the oil pump speed 28.18579267 corresponding to the second loss 24.91105675 is not less than the second speed, then the third speed is the second speed The oil pump speed corresponding to the loss 28.18579267 is 1500.

In the embodiment of the present application, when the multiple second losses are smaller than the first loss, the rotational speed of the oil pump is adjusted to the rotational speed of the oil pump corresponding to the lowest loss among the multiple second losses. In this way, the speed of the oil pump can be adjusted to minimize the loss, thereby improving the overall efficiency more effectively.

On the basis of any of the above embodiments, in a possible implementation manner, in the correlation relationship, the motor speed, the oil pump speed and the loss are a continuous functional relationship.

In a possible way of understanding, when the correlation is a table based on the relationship between different oil pump speeds and motor speeds and the corresponding losses under different oil temperatures, since the test data is discrete data, it is impossible to accurately determine the corresponding first speed. of multiple second losses. For example, when the first speed is 150, but during the test, due to the discreteness of the values, the relationship between different motor speeds and the corresponding losses when the first speed is 150 is not tested, so from the table In 1, the multiple second losses when the first speed is 150 cannot be directly determined.

Therefore, in a possible implementation, a table can be established according to the relationship between different oil pump speeds, different motor speeds and corresponding losses under different oil temperatures, combined with interpolation method, for example, based on the discrete data in the table to supplement Insert a continuous function, so that this continuous curve passes through all discrete data points, and obtains the continuous functional relationship between the motor speed, the oil pump speed and the loss.

In a possible implementation, the different oil pump speeds, motor speeds and corresponding losses obtained by testing at different oil temperatures can be used as samples for training the neural network model, and a continuous functional relationship between motor speed, oil pump speed and loss can be obtained. .

After obtaining the first rotational speed of the motor, the second rotational speed of the oil pump and the temperature of the casing lubricating oil, a plurality of second losses corresponding to the first rotational speed are determined through the functional relationship corresponding to the temperature, thereby controlling the rotational speed of the oil pump. Wherein, the control method of the rotational speed of the oil pump may correspond to the description in the above-mentioned embodiment, and will not be repeated here.

In the embodiment of the present application, the motor speed, the oil pump speed and the loss are in a continuous functional relationship, so that multiple second losses corresponding to the first speed can be more accurately determined, so that the oil pump speed is adjusted to the speed corresponding to the lowest loss, Improve overall efficiency more effectively.

The methods of the embodiments of the present application have been described above with reference to FIG. 4 to FIG. 9 , and the following describes the control apparatuses provided by the embodiments of the present application for executing the above methods. Those skilled in the art can understand that the methods and apparatuses may be combined and referenced with each other, and a control apparatus provided in the embodiments of the present application may execute the steps of the above-mentioned control method.

The following is an example of dividing each function module corresponding to each function to illustrate:

As shown in FIG. 10 , FIG. 10 shows a schematic structural diagram of a control apparatus provided by an embodiment of the present application. The control device includes: a processing unit 1001 . The processing unit 1001 is configured to complete the step of controlling the rotational speed of the oil pump.

An example, taking the control device as a terminal device or a chip or a chip system applied in the terminal device as an example, the processing unit 1001 is configured to support the control device to perform S601 to S602, S801 to S803 or S901 and S902 in the above embodiment Wait.

In a possible embodiment, the control apparatus may further include: a communication unit 1002 and a storage unit 1003 . The processing unit 1001, the communication unit 1002, and the storage unit 1003 are connected through a communication bus.

The storage unit 1003 may include one or more memories, and the memories may be devices in one or more devices or circuits for storing programs or data.

The storage unit 1003 may exist independently, and is connected to the processing unit 1001 of the control device through a communication bus. The storage unit 1003 may also be integrated with the processing unit.

The control apparatus may be used in a communication device, circuit, hardware component or chip.

Taking the control apparatus as the terminal device in the embodiment of the present application as an example, the communication unit 1002 may be an input or output interface, a pin, a circuit, or the like. Exemplarily, the storage unit 103 may store computer execution instructions of the method of the terminal device, so that the processing unit 1001 executes the method of the terminal device in the above-mentioned embodiments. The storage unit 1003 may be a register, a cache or a RAM, etc., and the storage unit 1003 may be integrated with the processing unit 101. The storage unit 1003 may be a ROM or other types of static storage devices that may store static information and instructions, and the storage unit 1003 may be independent of the processing unit 1001 .

An embodiment of the present application provides a control device, where the control device includes one or more modules for implementing the methods in the steps included in the foregoing FIG. - The steps of the method in the steps contained in Figure 8 correspond. Specifically, for each step in the method performed by the terminal device in the embodiment of the present application, there is a unit or module in the terminal device that executes each step in the method. For example, a module that performs control of the rotational speed of the oil pump may be referred to as a processing module. A module that performs the steps of processing messages or data on the control device side can be referred to as a communication module.

FIG. 11 is a schematic structural diagram of a powertrain provided by an embodiment of the application. As shown in FIG. 11 , the powertrain includes a control device 1101 , an inverter 1102 , a motor 1103 , and a reducer 1104 .

The control device 1101 may correspond to the description in FIG. 10 , which is not repeated in this embodiment of the present application.

The inverter 1102 is used to convert the direct current into alternating current and then transmit it to the motor 1103.

The motor 1103 is used to convert alternating current into mechanical energy to drive the vehicle.

The speed reducer 1104 is used to convert the output rotational speed of the motor shaft of the motor 1103 .

FIG. 12 is a schematic structural diagram of a vehicle according to an embodiment of the application. As shown in FIG. 12 , the vehicle includes: a power battery pack 1201 and a power assembly 1202 .

For the powertrain 1202, reference may be made to the description in FIG. 11 , and details are not described herein again in this embodiment of the present application.

The power battery pack 1201 provides DC power for the inverter of the powertrain 200 .

FIG. 13 is a schematic structural diagram of a chip 130 provided by an embodiment of the present invention. The chip 130 includes one or more (including two) processors 1313 and a communication interface 1330 .

In a possible embodiment, the chip 130 shown in FIG. 13 further includes a memory 1340 , which may include read-only memory and random access memory, and provides operation instructions and data to the processor 1313 . A portion of memory 1340 may also include non-volatile random access memory (NVRAM).

In some embodiments, memory 1340 stores the following elements, executable modules or data structures, or a subset thereof, or an extended set of them:

In this embodiment of the present invention, the corresponding operation is performed by calling the operation instruction stored in the memory 1340 (the operation instruction may be stored in the operating system).

A possible implementation manner is: the structure of the chips used by the terminal equipment, the wireless access network device or the session management network element is similar, and different devices may use different chips to realize their respective functions.

The processor 1313 controls the operation of the terminal device, and the processor 1313 may also be referred to as a central processing unit (central processing unit, CPU). Memory 1340 may include read-only memory and random access memory, and provides instructions and data to processor 1313 . A portion of memory 1340 may also include non-volatile random access memory (NVRAM). For example, the memory 1340, the communication interface 1330, and the memory 1340 are coupled together through the bus system 1320, where the bus system 1320 may include a power bus, a control bus, a status signal bus, and the like in addition to a data bus. However, for clarity of illustration, the various buses are labeled as bus system 1320 in FIG. 13 .

The above communication unit may be an interface circuit or a communication interface of the device for receiving signals from other devices. For example, when the device is implemented in the form of a chip, the communication unit is an interface circuit or a communication interface used by the chip to receive or transmit signals from other chips or devices.

The methods disclosed in the above embodiments of the present invention may be applied to the processor 1310 or implemented by the processor 1010 . The processor 1310 may be an integrated circuit chip with signal processing capability. In the implementation process, each step of the above-mentioned method may be completed by an integrated logic circuit of hardware in the processor 1310 or an instruction in the form of software. The above-mentioned processor 1310 may be a general-purpose processor, a digital signal processor (digital signal processing, DSP), an application specific integrated circuit (ASIC), an off-the-shelf programmable gate array (field-programmable gate array, FPGA) or Other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. Various methods, steps, and logical block diagrams disclosed in the embodiments of the present invention can be implemented or executed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in conjunction with the embodiments of the present invention may be directly embodied as executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules may be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other storage media mature in the art. The storage medium is located in the memory 1040, and the processor 1310 reads the information in the memory 1340, and completes the steps of the above method in combination with its hardware.

In a possible implementation manner, the communication interface 1330 is configured to perform the steps of receiving and sending the terminal equipment, radio access network device or session management network element in the embodiments shown in FIGS. 4-9 . The processor 1310 is configured to perform processing steps of the terminal device in the embodiments shown in FIG. 4 to FIG. 9 .

In the above-described embodiments, the instructions stored by the memory for execution by the processor may be implemented in the form of a computer program product. The computer program product can be pre-written in the memory, or downloaded and installed in the memory in the form of software.

A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the procedures or functions according to the embodiments of the present application are generated in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable device. Computer instructions may be stored on or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server, or data center over a wire (e.g. coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (eg, infrared, wireless, microwave, etc.) to another website site, computer, server, or data center. The computer-readable storage medium can be any available medium that can be stored by a computer or a data storage device such as a server, data center, etc. that includes one or more available media integrated. Useful media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, DVDs), or semiconductor media (eg, solid state disks, SSDs), and the like.

Embodiments of the present application also provide a computer-readable storage medium. The methods described in the above embodiments may be implemented in whole or in part by software, hardware, firmware or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media can include both computer storage media and communication media and also include any medium that can transfer a computer program from one place to another. The storage medium can be any target medium that can be accessed by a computer.

As one possible design, the computer readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium intended to carry or in an instruction or data structure The required program code is stored in the form and can be accessed by the computer. Also, any connection is properly termed a computer-readable medium. For example, if you use coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies (such as infrared, radio, and microwave) to transmit software from a website, server, or other remote source, coaxial cable, fiber optic cable , twisted pair, DSL or wireless technologies such as infrared, radio and microwave are included in the definition of medium. Disk and disc as used herein includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention. should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention. should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

A control method, characterized in that it is applied to an electric drive system, the electric drive system includes an oil pump, a motor, a reducer and a casing, the motor and the reducer are arranged in the casing, and the engine A lubricating oil is stored in the casing, and the oil pump is used for pumping the lubricating oil, and the method includes:

Obtain the first rotational speed of the motor, the second rotational speed of the oil pump and the temperature of the lubricating oil in the casing;

According to the first rotational speed, the second rotational speed and the temperature, the rotational speed of the oil pump is controlled to be a third rotational speed.
The method according to claim 1, wherein the controlling the rotation speed of the oil pump to be the third rotation speed according to the first rotation speed, the second rotation speed and the temperature comprises:

According to the temperature, determine the correlation relationship corresponding to the temperature, and the correlation relationship includes the correlation relationship between the motor speed, the oil pump speed and the loss;

determining a first loss corresponding to the first rotational speed and the second rotational speed in the association relationship;

According to the first loss and the correlation relationship, the rotational speed of the oil pump is controlled to be a third rotational speed.
The method according to claim 2, wherein the controlling the rotational speed of the oil pump to be a third rotational speed according to the first loss and the correlation relationship comprises:

determining a plurality of second losses corresponding to the first rotational speed in the association relationship;

In the case where one of the second losses is smaller than the first loss, the rotational speed of the oil pump is adjusted to be the third rotational speed, wherein the third rotational speed is the rotational speed of the oil pump corresponding to the one of the second losses .
The method according to claim 3, characterized in that, when one of the second losses is smaller than the first loss, adjusting the rotational speed of the oil pump to be the third rotational speed, comprising:

In the case where the plurality of second losses are smaller than the first losses, the rotational speed of the oil pump is adjusted to be the third rotational speed, wherein the third rotational speed corresponds to the lowest loss among the plurality of second losses oil pump speed.
The method according to any one of claims 2-4, wherein the loss includes: oil churning loss and oil pump power consumption; wherein the oil churning loss is caused by the speed reducer gear in the casing The power loss caused by the liquid resistance caused by the rotation in the lubricating oil inside.
The method according to any one of claims 2-5, wherein, in the correlation relationship, the motor speed, the oil pump speed and the loss are a continuous functional relationship.
A control device is characterized in that it is applied to an electric drive system, the electric drive system includes an oil pump, a motor, a reducer and a casing, the motor and the reducer are arranged in the casing, and the engine A lubricating oil is stored in the casing, and the oil pump is used for pumping the lubricating oil, and the device includes:

a processing unit, configured to acquire the first rotational speed of the motor, the second rotational speed of the oil pump and the temperature of the lubricating oil in the casing;

The processing unit is further configured to control the rotational speed of the oil pump to be a third rotational speed according to the first rotational speed, the second rotational speed and the temperature.
The device according to claim 7, wherein the processing unit is further configured to:

According to the temperature, the correlation relationship corresponding to the temperature is determined, and the correlation relationship includes the correlation relationship between the motor speed, the oil pump speed and the loss;

determining a first loss corresponding to the first rotational speed and the second rotational speed in the association relationship;

According to the first loss and the correlation relationship, the rotational speed of the oil pump is controlled to be a third rotational speed.
The device according to claim 8, wherein the processing unit is further configured to:

determining a plurality of second losses corresponding to the first rotational speed in the association relationship;

In the case where one of the second losses is smaller than the first loss, the rotational speed of the oil pump is adjusted to be the third rotational speed, wherein the third rotational speed is the rotational speed of the oil pump corresponding to the one of the second losses .
The device according to claim 9, wherein the processing unit is further configured to:

In the case where the plurality of second losses are smaller than the first losses, the rotational speed of the oil pump is adjusted to be the third rotational speed, wherein the third rotational speed corresponds to the lowest loss among the plurality of second losses oil pump speed.
The device according to any one of claims 8-10, wherein the loss includes: oil churning loss and oil pump power consumption; wherein, the oil churning loss is caused by the loss of the reducer gear in the casing The power loss caused by the liquid resistance caused by the rotation in the lubricating oil inside.
The device according to any one of claims 8-11, wherein, in the correlation relationship, the motor speed, the oil pump speed and the loss are a continuous functional relationship.
A control device, characterized by comprising: a processor for calling a program in a memory to execute the method according to any one of claims 1-6.
A powertrain, comprising the control device according to any one of claims 7-12, the powertrain further comprising: an inverter, a motor and a reducer;

the inverter is used to convert the direct current into alternating current and then transmit it to the motor;

the motor, for converting the alternating current into mechanical energy to drive the vehicle;

The speed reducer is used to convert the output rotational speed of the motor shaft of the motor.
A vehicle, characterized in that, the vehicle comprises the power assembly of claim 14 and a power battery pack, wherein the power battery pack is used to provide DC power for an inverter.
A chip, characterized by comprising: a processor and an interface circuit, wherein the interface circuit is used for communicating with other devices, and the processor is used for executing the method of any one of claims 1-6.
A computer-readable storage medium, characterized in that the computer-readable storage medium stores instructions, which, when executed, cause a computer to execute the method according to any one of claims 1-6.